When Brazilian-born Carlos Moraes first arrived in New Zealand he worked as a kitchen hand, trained to be a chef and cooked in some of the best seafood restaurants in Queenstown. Now, instead of frying fish he’s studying them for his Master of Science in Biological Sciences at the University of Waikato’s Tauranga campus.
Carlos is analysing the changes during the sexual transitioning from female to male of the temperate wrasse (Notolabrus celidotus), more commonly known as the ‘spotty’. It’s important research and, with access to spotties within a stone’s throw from the Coastal Marine Research Centre at Sulphur Point, Carlos reckons he’s struck gold with his study path.
“My three daughters benefit from more time with me than the hospitality industry allowed and I’ve worked with world-class marine researchers as part of my studies. It’s a fantastic lifestyle,” he enthuses.
Two such researchers, Waikato’s Chair in Coastal Science, Professor Chris Battershill and finfish reproductive physiologist Dr Simon Muncaster from Toi Ohomai, are Carlos’s supervisors. They espouse the importance of his work to advance the spotty as a possible indicator species for research.
“Understanding how species reproduce is central to ensuring their long-term survival,” says Professor Battershill. “For fish species this is now critical as fisheries the world over are under substantial threat from both fishing pressure and habitat degradation. Working on ‘spotties’ allows investigation of physiological processes relevant to other fish. Of significance is the increasing presence of persistent pharmaceuticals, especially hormones, finding their way through waste water to the sea which can influence reproduction in fish. Carlos's work will provide an important piece for putting together the puzzle of how fish survive in an increasingly 'human' modified coastal ecosystem.”
Carlos’s research also ties into a larger project Dr Muncaster is working on. “This wider study focuses on understanding the mechanisms and biological pathways directing sex change in fish and is a close collaboration with partners at the University of Otago,” says Dr Muncaster.
The study path has come full circle for Carlos who initially started an Aquaculture Engineering degree at the Federal University of Santa Catarina. Living in a coastal town, he’d always felt connected to the ocean and aquaculture played a huge part in the local economy with many restaurants having their own oyster or mussel farms.
“Growing up and eating the freshest seafood opened my eyes to aquaculture and its benefits to the food industry, as well as relieving the pressure of wild fishing.”
But the studies were put on hold when he booked a one-way ticket to New Zealand. “I had a great life in Brazil but I wanted to be independent and find my own path. Somehow, I knew I’d return to my marine studies one day.”
Taking the advice of a neighbour who’d made a successful move from Brazil to Queenstown, Carlos followed suit. He found kitchen work easy to come by and used his spare time indulging his adventurous spirit with every outdoor pursuit the far South had on offer. Eventually he studied to become a chef and spent several years in the business but when he met and married Scottish-born Fiona and started a family, the stress of 6am to 11pm shifts took a toll.
Checking study options online, Carlos discovered the former Bay of Plenty Polytechnic’s (now Toi Ohomai Institute of Technology) Diploma in Marine Studies and his passion for aquaculture was reignited. The family relocated to the Bay of Plenty and, with Fiona’s support, Carlos started with the diploma and used the pathway in his third year to transition into the University of Waikato’s Bachelor of Science in Biological Sciences. He’s now in the final stages of his masters with Waikato.
For his thesis Carlos opted to study the spotty over the shark, given fieldwork with sharks is a little trickier. The spotty is neither endangered nor targeted by commercial fishing, handles captive life very well and, according to Carlos, is “a very interesting little fish.”
Interesting is an understatement – what the temperate wrasse spotty may lack in size and notoriety, compared to a shark, it more than makes up for with its ability to change sex. When the male spotty is removed from its harem of female fish, the dominant female begins her sexual transition to fill his place.
From the time the male spotty is removed, changes in the dominant female happen fast. Her egg production stops and she starts producing spermatozoa. The process takes around two months and changes occur externally as well as internally. The endocrine system changes, the anal fin of the female changes from yellow to a blue/grey transparent colour and the two black spots on the back of the female move upwards toward the dorsal fin resembling more of a smudge. The external changes are the primary focus of Carlos’s research. Tracking these changes may sound voyeuristic but it’s all in the name of science.
There are other big studies on sex changing wrasses happening abroad but mostly about the tropical species. “Little has been done to document the temperate species we have in New Zealand,” says Carlos. “Visually speaking, it’s easy to identify a female from a male but the analysis of the external markings has never, to my knowledge, been done here.”
Once he’s completed his masters the keen surfer wants to stay in the Bay and work as a Marine Biologist with a view to embarking on a PhD in the future.
His family back in Brazil couldn’t be more proud. “Especially my mother,” says Carlos with a wide smile. “She can see that coming to New Zealand has been the best thing for me. I have a beautiful family, live in this amazing city and am doing what I love. I’m a very lucky man.”